The objective of this proposal is to evaluate using siRNA agent to knockdown pro-angiogenic genes as a treatment for HSV infection of eyes that can result the blinding lesions of stromal keratitis (SK). Recurrence of herpes simplex virus (HSV) infection is the most common infectious cause of corneal blindness in the U. S., and there is no efficient medication available. The latest studies have revealed that HSV infection stimulates the expression of VEGF, resulting in corneal neovascularization (NV). Several antagonists of VEGF pathway tested have been shown to block this ocular NV in animal models. Differing from VEGF micro-pocket pellet inoculation model, a mouse eye model with over-expression of VEGF stimulated by purified HSV DNA or synthetic CpG-motif oligonucleotides, represents a clinically relevant model for treatment of corneal NV. Gene silencing by RNA interference (RANi) has been one of the most significant breakthroughs in biomedical research for the last decade. It provides a rapid and reliable tool for gene discovery or gene validation; and holds the great potential as new therapeutics to cure human diseases. A method for effective siRNA delivery into clinically relevant xenograft tumor has been successfully developed, to knockdown pro-angiogenic genes, hVEGF and/or mVEGFR-2, and to inhibit tumor growth. This method provides a strong foundation for development of the in vivo siRNA delivery into the animal model of ocular neovascularization (NV) diseases, for which the VEGF-mediated angiogenesis pathway was validated as a key target for therapeutic intervention. Using this model system with effective siRNA-mediated gene knockdown, a possible VEGF pathway-antagonistic approach as a novel therapeutics will be demonstrated. The long-term goal of this study is to develop RNAi drug to cure various eyes diseases caused by the excessive angiogenesis. The specific aims of the phase I study include: 1) Select best siRNA duplexes for knockdown of mVEGF and mVEGF R1, R2 in vitro; 2) Optimize local administration of siRNA into murine eye tissues with reporter genes; 3) Achieve siRNA-mediated knockdown of mVEGF and mVEGF R1, R2 in mice eyes; and 4) Reverse ocular neovascularization process caused by HSV infection with the siRNA-mediated anti-angiogenesis. The completion of these objectives will lead to a Phase II study with a pre-clinical setting for the novel therapeutics to cure herpetic SK and other angiogenic eye diseases.